Problem with rotary valve

[jma78]

I've got some problems with the 4th valve on my B&S F-tuba (rotary valves)

The problem is that it moves slower than the other valves. Otherwise it's fine, the resistance is the same troughout the whole range of movement, and there are no extra noises or anything like that. Just that i moves slower... (it feels like there is grease in the valve...)

I've opened the valve twice and cleaned it and oiled it. Put it back togheter, but the problem is still there.

Any idea what could be causing this???

I can go to a repair shop erliest mabye in the end of next week, so I wish i could fix this ASAP myself. It's possible to play on the tuba, it just irritates me that the 4th valve moves slower....

Any help appreciated.

[rocksanddirt]

Without any special knowledge of slow valves, you might try to soak the rotor for an hour in vinegar, then reassemble, oil up and see if it still sticks. Worked wonders on an older horn that I just bought.

Another idea is to check the linkage, maybe that's where the stickiness is from?

good luck!

[jma78]

Instant idea:

Disconnect the linkage of the slow valve and one of the "faster " valves,remove the stop bumpers? holders.
Spin the valves,if they feel like being similar fast,you should inspect your linkage.

Then continue in searching........

Best regards from germany,

Kurt

Yes, I have done this. The problem is in the valve (it doesn't spin) not in the linkage.

rocksanddirt: I will try with vinegar.


Thanks for your help this far...

[iiipopes]

Make sure to rinse completely, the tubing and bugle as well as the valve, when done so as to preclude corrosion possibilities.

[eupher61]

it sounds like the bearing plate isn't straight. That would be my first check, take the bearing plate off and turn the valve in the casing. If that works, it's the bearing plate not being in place. Don't use a hammer or anything to put the plate back on, use the back cap, hand tighten it as much as you can, tap the center of the cap with a wood or rawhide hammer, repeat until it's down tight.

If that still doesn't work, have a repair shop person go over it and check the tubing. It might be a little bit bent out of line.

You're SURE it isn't the linkage? If you have the same valves as me, the screw the connects onto the valve can get too tight. Drop some oil into it (STP really does work well for oiling linkages that are a bit old) and tighten it just enough to hold without excess movement.

[jon112780]

What you could do to hold you over before getting the horn in to the shop over the weekend; get a rubber band and loop one edge around a brace near the valves and the other underneath the linkage. The size/strength is up to you, but this might be the quickest (temporary) fix.

In high school, I used the school's 1970's 186 BBb that had the slowest valves known to man. I didn't want to take the two weeks off of the horn to send it into the shop, and the the band director had other (unplayable)horns that had higher priority, so I used rubber bands on all four valves. They weren't the lightest valves, but they were mighty quick; and for only playing 2 hours a day, it wasn't really that troublesome on my hand.

[jma78]

Well, just finished cleaning the 4th valve. Now it's working better than when tuba was new!!!!!!!!!! There must have been grease in the valve.

-Degrease
-Rinse with water
-Soak in vinegar
-Rinse with water
-Oil and put back together

I had an unopened tube of the red Conn grease. Actually I've never used it before.

So, Thanks to everybody for your help!


-J-